Concrete pile with bulb at lower end



March 30, 1948.

M. M. UPSON ET AL 2,438,729 CONCRETE PILE WITH BULB AT LOWER EN D Filed Sept. 5, 19 .5 -6 sheets-sheet 1 March 30, 1948. M, UPSON ET AL 2,438,729

CONCRETE PILE WITH BULB AT LOWER END Filed Sept. 5, 1945 6 Sheets-Sheet 2 h uvgfNroRs March 30, 1948. UPSON ET AL 2,438,729

' CONCRETE FILE WITH BULB AT LOWER END Filed Sept. 5, 1945 6 Sheets-Sheet 3 INVEITOgS ATTUfi/YEY March 30, 1 M. M. UPSON ET AL CONCRETE FILE WITH BULB AT LOWER END Filed Sept. 5, 1945 6 Sheets-Sheet 4 INVENTgfRS "3 q M gm al 1:;

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March 30, 1948. UPSON ET AL Y 2,438,729

CONCRETE FILE WITH BULB AT LOWER END Filed Sept. 5, 1945 s Sheets-Sheet 6 1474 ZTZQ Y Patented Mar. 30, 1948 CONCRETE PILE WITH BULB AT- LOWER END Maxwell M. Upson, Englewood, and Elihu D. Watt, Plainfield, N. J., assignors to Raymond Concrete Pile Company, New York, N. Y., a corporation of New Jersey Application September 5, 1945, Serial No. 614,460

9 Claims. 1

This invention relates to concrete piles of the type having an enlarged base or bulb which provides an increased load bearing area, and it has for an object to simplify and strengthen the construction of such piles.

Another object of the invention is to provide an improved pile having a bulbous base of controlled shape and location which is firmly anchored to the superposed concrete column.

Another object is to provide a novel and improved pile of the foregoing type having a permanent shell which contains the concrete and which is anchored to the bulb.

Still another object is to provide an improved method of forming a concrete pile with a bulbous base.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed.

In the art of driving piles it has been customary for many years to make a pile with a bulb on the lower end for the purpose of distributing weight over an area larger than the normal point of the pile. Such a bulb may be particularly useful in locations where rock or hardpan can not be reached but whereunderlying sand or clay of substantial bearing yalue exists. By the use of the bulb the increased area of the point which reaches a substantial lower stratum may provide greater carrying power than would be possible on the normal area of the pile point.

For the formation of a bulb pile, the usual method involves the use of a casing driven by an internal core. A sheet metal pan, a boot, or dry concrete may be used at the lower end of the casing to exclude dirt and water. After the core and easing are driven to the proper depth, the core is withdrawn, concrete is dropped into the bottom of the casing, the casing is partially withdrawn, and the concrete then driven out by means of the core to form the bulb.- The casing is then filled with concrete to ground level or higher, and with the core resting on the concrete the casing is pulled. This forms the socalled shell-less bulb pile. In some cases a shell is dropped inside the casing after the bulb is formed, and this shell is filled with concrete on which the core rests while the casing is withdrawn.

One of the serious weaknesses of the shell-less bulb pile is that the earth pressures developed by the forming of the bulb tend to distort the unset concrete, thereby reducing the cross-sectional area of the column of the pile, particularly where it connects with the bulb. The use of a shell naturally tends to overcome this diiliculty but introduces other weaknesses that materially reduce the load-carrying capacity of the'pile. This is due to the decreased cross-section of theinner shell which permits the soil to lose its compression when the outer casing is withdrawn. Furthermdrathe reduced area of the column lessens the allowable load on'the concrete, thereby decreasing the allowable load on the pile.

Another weakness of the shell-less and droppeddn-shell bulb pile which has never been overcome is that the heaving of the ground caused by the driving of adjacent piles may lift the column away from the bulb, severing the concrete. It is evident that in order to insure the continuity of the pile unit some method of fastening the bulb to the column must be provided.

The present invention overcomes the foregoing disadvantages of the prior art by the novel ,method and structure hereinafter described and provides a pile in which a permanent left-inthe-ground shell is driven in intimate contact with the ground and maintains the pressure developed by the displacement of the material penetrated. It also provides an improved method of anchoring the concrete column to the shell and to the bulb. i

Although the novelfeatures which are characteristic of this invention are set forth more in detail in the claims appended hereto, the nature and scope of the invention may be better understood'by referring to the following description, taken in connection with the accompanying drawings forming a part thereof, in which certaln specific embodiments have been set forth for purposes of illustration.

In the drawings:

Figures 1 and'2 are vertical sectional views showing the preferred method of inserting the rod of our bulb-anchoring device athroughthe core in the pile casing preparatory to driving the pile;

Figs. 3 to 7 are vertical sectional views illustrating the several steps. of forming the pile when using the bulb-anchoring devices of Figs. 1 and 2;

Fig. 8 is a similar sectional view of the complete pile; v I 1 Figs. 9 to 12 are vertical sectional views illustrating a method of driving the pile with a different form of bulb anchor; and

Figs. 13 to 16 are similar views illustrating another method of driving the pile throughthe s eared bulb and secured to said superstructure for anchoring aforesaid parts of the pile together.

2. A concrete pile, comprising a superstructure including a shell constructed and arranged to be driven into the ground and to remain in intimate contact with the ground at the position to which it is driven, and including a concrete column formed in situ and filling the inside of said shell and in intimate contact therewith substantially throughout its length; an enlarged concrete bulb integral with and at the lower end of said column beneath said shell and formed in situ therewith; and anchoring means including a member engaging the lower end of said bulb, and at least one rod secured to said member and extending longitudinally through said column, embedded in the concrete therein, for anchoring said bulb and said column together,

3. A concrete pile, comprising a superstructure including a shell constructed and arranged to be driven into the ground and to remain in intimate contact with the gI'OllIld at the position to which it is driven, and including a concrete column formed in situ and filling the inside of said shell and in intimate contact therewith substantially throughout its length; an enlarged concrete bulb integral with and at the lower end of said column beneath said shell and formed in situ therewith; and an anchoring device including a plate engaging the lower end of said bulb and a rod secured to said plate and embedded in said bulb and said column to anchor the bulb and column together.

4. A concrete pile, comprising a superstructure including a shell constructed and arranged to be driven into the ground and to remain in intimate contact with the ground at the position to which it is driven, and including a concrete column formed in situ and filling the inside of said shell and in intimate contact therewith substantially throughout its length; an enlarged concrete bulb integral with and at the lower end of said column beneath said shell and formed in situ therewith; and an anchoring member including a plate engaging the lower end of said bulb, and a plurality of bars, secured to said plate, embedded in said bulb and rigidly secured to said shell, for anchoring said bulb to said shell.

5. Method of forming a concrete pile with a bulbous base which comprises driving a casing and a surrounding shell into the ground with said casing projecting below said shell, depositing concrete in said casing, partially withdrawing said casing while leaving said surrounding shell in its driven position so as to leave concrete in the ground therebeneath, exerting pressure on the concrete in said casing to drive the concrete into the ground to form a bulb below the end of said shell and in contact therewith, and withdrawing said casing from inside said shell to leave the shell at its driven position in the ground supported at its lower end upon said bulb.

6. Method of forming a concrete pile with a bulbous base which comprises driving a casing and a surrounding shell into the ground with said casing projecting below said shell, filling the lower end of said casing with concrete, partially withdrawing said casing while leaving said surrounding shell in its driven position so as to leave concrete in the ground therebeneath, exerting pressure on the concrete in said casing to drive the concrete into the ground to form a bulb below the end of said shell and in contact therewith, removing said casing from the ground without movement of said shell from its driven position, and filling said shell with concrete to form a column inside said shell integral with said bulb.

7. Method of forming a concrete pile with a bulbous base which comprises driving an anchoring member and a shell into the ground with said anchoring member extending into a hole in the ground beneath said shell and said shell in intimate contact with the ground into which it. is driven, depositing concrete in said hole about said anchoring member, exerting pressure on said concrete to drive same into the ground to form a bulb surrounding said anchoring member and extending upwardly into said shell, and filling said shell with concrete while it remains in its driven position in the ground as a permanent part of the pile.

8. Method of forming a concrete pile with a bulbous base, which comprises inserting an elongated anchoring rod having a bottom plate in a casing having a surrounding shell, driving the parts thus assembled into the ground with said plate below said casing and with said casing proiecting below said shell, filling the lower end of said casing with concrete stacked on said plate, partially withdrawing said casing so as to leave concrete in contact with the ground and plate therebeneath, exertin pressure on the concrete in said casing to drive said concrete into the ground to form a bulb engaging said plate and said rod, removing said casing from the ground, and filling said shell with concrete surrounding said rod.

9. Method of forming a concrete pile with a bulbous base, which comprises securing an openirame anchoring member having a bottom plate to the lower end of a cylindrical shell, placing a cylindrical casing inside said shell, driving the parts thus assembled into the ground with said plate in advance and with said casing projecting below said shell, filling the lower end of said casing with concrete resting on top of said plate, partially withdrawing said casing so as to leave concrete in contact with the ground surrounding said anchoring member, exerting pressure on the concrete in said casing to drive said concrete into the ground to form a bulb surrounding said anchoring member, removing said casing from the ground, and filling said shell with concrete.

MAXWELL M. UPSON. ELII-IU D. WATT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 890,765 Gilbreth June 16, 1908 961,492 Goldsborough June 14, 1910 1,642,213 Neelands Sept. 13, 1927 1,884,129 Nadel Oct. 25, 1932 1,978,332 Stern Oct. 23, 1934: 2,027,511 Bertran Jan. 14, 1936 

